Area forecast discussion National Weather Service Des Moines Iowa 638 PM CDT Thursday may 23 2013 Short term.../tonight /... issued at 310 PM CDT Thursday may 23 2013 Little of concern tonight with Iowa between High Plains ridge and departing Great Lakes trough. Although skies will be clear with light winds as surface high pressure crosses the upper MS valley...overnight lows should only dip into the upper 30s northeast keeping frost concerns at Bay. Long term.../Friday through Thursday/... issued at 310 PM CDT Thursday may 23 2013 Active period setting up for the Holiday weekend into next week...with main issued surrounding chances for thunderstorms and potential for heavy rain. High pressure initially over the area Friday with dry conditions expected...however the surface high quickly shoves east with warm air advection and moisture advection back into western Iowa by late Friday afternoon. This will allow for some potential thunderstorms across western Iowa late in the afternoon. Chances for thunderstorms to become more widespread across the County Warning Area as weak shortwaves push eastward through the upper level ridge expected to remain in place through the weekend. Thunderstorm chances will remain with the climatological favored times in this type of pattern...mainly in the evening to overnight hours and lingering into the morning. With the extended chances for thunderstorms and rainfall...flash flooding and river flooding becomes a concern. Moisture transport oriented into Iowa for much of the Holiday weekend...precipitable waters well above average increasing into the 1.3 to 1.5 inch range...and fz level quite high suggesting efficient rain production through the weekend. Widespread rainfall amounts of 1 to 2 inches with locally higher amounts are possible through the Holiday weekend. Severe parameters not that great...so widespread severe weather is not anticipated. Upper level ridge begins to shift east slightly and dampen some...with a surface warm front expected to lift northward through the state Tuesday. An upper level closed low digs into the Desert Southwest with impulses ejecting out ahead of the main system through the region. With the warm front stalling out across the County Warning Area Tuesday into Wednesday...and the energy lifting through the area...thunderstorm chances continue into next week across the area. Warmer temperatures also expected with the warm front lifting north...with much of the area returning to 70s and 80s by the middle of next week. && Aviation...24/00z issued at 637 PM CDT Thursday may 23 2013 Few concerns this period. High remains over the area through overnight hours as trough of low pressure over the Western Plains drifts east Friday. In response some high and middle level clouds will increase for kfod and kdsm 15-22z. Winds will increase from the south southeast at kfod and kdsm as well from 14z-00z with gusts to 20kt after 16-20z. None weather until system arrives after 00z with nocturnal thunder likely becoming more problematic for ceilings and visibilities after 04z...and will include more details next update. && Dmx watches/warnings/advisories... none. && $$ Short term...small long term...beerends aviation...rev